EMAG2 is a global Earth Magnetic Anomaly Grid compiled from satellite, ship, and airborne
magnetic measurements. It is a significant update of our previous candidate grid for
the World Digital Magnetic Anomaly Map. The resolution has been improved from 3 arc-minutes
to 2 arc-minutes, and the altitude has been reduced from 5 km to 4 km above the geoid.
Additional grid and track line data have been included, both over land and the oceans.
Wherever available, the original shipborne and airborne data were used instead of
precompiled oceanic magnetic grids. Interpolation between sparse track lines in the
oceans was improved by directional gridding and extrapolation, based on oceanic crustal
age model. The longest wavelengths (>330 km) were replaced with the latests CHAMP
satellite magnetic field model MF6.